1 /*-
2 * Copyright (c) 1993, David Greenman
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/param.h>
31 #include <sys/exec.h>
32 #include <sys/imgact.h>
33 #include <sys/imgact_aout.h>
34 #include <sys/kernel.h>
35 #include <sys/limits.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/proc.h>
40 #include <sys/racct.h>
41 #include <sys/resourcevar.h>
42 #include <sys/signalvar.h>
43 #include <sys/syscall.h>
44 #include <sys/sysent.h>
45 #include <sys/systm.h>
46 #include <sys/vnode.h>
47
48 #include <machine/frame.h>
49 #include <machine/md_var.h>
50
51 #include <vm/vm.h>
52 #include <vm/pmap.h>
53 #include <vm/vm_map.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_param.h>
56
57 #ifdef __amd64__
58 #include <compat/freebsd32/freebsd32_signal.h>
59 #include <compat/freebsd32/freebsd32_util.h>
60 #include <compat/freebsd32/freebsd32_proto.h>
61 #include <compat/freebsd32/freebsd32_syscall.h>
62 #include <compat/ia32/ia32_signal.h>
63 #endif
64
65 static int exec_aout_imgact(struct image_params *imgp);
66 static int aout_fixup(register_t **stack_base, struct image_params *imgp);
67
68 #if defined(__i386__)
69 struct sysentvec aout_sysvec = {
70 .sv_size = SYS_MAXSYSCALL,
71 .sv_table = sysent,
72 .sv_mask = 0,
73 .sv_errsize = 0,
74 .sv_errtbl = NULL,
75 .sv_transtrap = NULL,
76 .sv_fixup = aout_fixup,
77 .sv_sendsig = sendsig,
78 .sv_sigcode = sigcode,
79 .sv_szsigcode = &szsigcode,
80 .sv_name = "FreeBSD a.out",
81 .sv_coredump = NULL,
82 .sv_imgact_try = NULL,
83 .sv_minsigstksz = MINSIGSTKSZ,
84 .sv_pagesize = PAGE_SIZE,
85 .sv_minuser = VM_MIN_ADDRESS,
86 .sv_maxuser = VM_MAXUSER_ADDRESS,
87 .sv_usrstack = USRSTACK,
88 .sv_psstrings = PS_STRINGS,
89 .sv_stackprot = VM_PROT_ALL,
90 .sv_copyout_strings = exec_copyout_strings,
91 .sv_setregs = exec_setregs,
92 .sv_fixlimit = NULL,
93 .sv_maxssiz = NULL,
94 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32,
95 .sv_set_syscall_retval = cpu_set_syscall_retval,
96 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
97 .sv_syscallnames = syscallnames,
98 .sv_schedtail = NULL,
99 .sv_thread_detach = NULL,
100 .sv_trap = NULL,
101 };
102
103 #elif defined(__amd64__)
104
105 #define AOUT32_USRSTACK 0xbfc00000
106 #define AOUT32_PS_STRINGS \
107 (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings))
108 #define AOUT32_MINUSER FREEBSD32_MINUSER
109
110 extern const char *freebsd32_syscallnames[];
111 extern u_long ia32_maxssiz;
112
113 struct sysentvec aout_sysvec = {
114 .sv_size = FREEBSD32_SYS_MAXSYSCALL,
115 .sv_table = freebsd32_sysent,
116 .sv_mask = 0,
117 .sv_errsize = 0,
118 .sv_errtbl = NULL,
119 .sv_transtrap = NULL,
120 .sv_fixup = aout_fixup,
121 .sv_sendsig = ia32_sendsig,
122 .sv_sigcode = ia32_sigcode,
123 .sv_szsigcode = &sz_ia32_sigcode,
124 .sv_name = "FreeBSD a.out",
125 .sv_coredump = NULL,
126 .sv_imgact_try = NULL,
127 .sv_minsigstksz = MINSIGSTKSZ,
128 .sv_pagesize = IA32_PAGE_SIZE,
129 .sv_minuser = AOUT32_MINUSER,
130 .sv_maxuser = AOUT32_USRSTACK,
131 .sv_usrstack = AOUT32_USRSTACK,
132 .sv_psstrings = AOUT32_PS_STRINGS,
133 .sv_stackprot = VM_PROT_ALL,
134 .sv_copyout_strings = freebsd32_copyout_strings,
135 .sv_setregs = ia32_setregs,
136 .sv_fixlimit = ia32_fixlimit,
137 .sv_maxssiz = &ia32_maxssiz,
138 .sv_flags = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32,
139 .sv_set_syscall_retval = ia32_set_syscall_retval,
140 .sv_fetch_syscall_args = ia32_fetch_syscall_args,
141 .sv_syscallnames = freebsd32_syscallnames,
142 };
143 #else
144 #error "Port me"
145 #endif
146
147 static int
148 aout_fixup(register_t **stack_base, struct image_params *imgp)
149 {
150
151 *(char **)stack_base -= sizeof(uint32_t);
152 return (suword32(*stack_base, imgp->args->argc));
153 }
154
155 static int
156 exec_aout_imgact(struct image_params *imgp)
157 {
158 const struct exec *a_out = (const struct exec *) imgp->image_header;
159 struct vmspace *vmspace;
160 vm_map_t map;
161 vm_object_t object;
162 vm_offset_t text_end, data_end;
163 unsigned long virtual_offset;
164 unsigned long file_offset;
165 unsigned long bss_size;
166 int error;
167
168 /*
169 * Linux and *BSD binaries look very much alike,
170 * only the machine id is different:
171 * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
172 * NetBSD is in network byte order.. ugh.
173 */
174 if (((a_out->a_midmag >> 16) & 0xff) != 0x86 &&
175 ((a_out->a_midmag >> 16) & 0xff) != 0 &&
176 ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86)
177 return -1;
178
179 /*
180 * Set file/virtual offset based on a.out variant.
181 * We do two cases: host byte order and network byte order
182 * (for NetBSD compatibility)
183 */
184 switch ((int)(a_out->a_midmag & 0xffff)) {
185 case ZMAGIC:
186 virtual_offset = 0;
187 if (a_out->a_text) {
188 file_offset = PAGE_SIZE;
189 } else {
190 /* Bill's "screwball mode" */
191 file_offset = 0;
192 }
193 break;
194 case QMAGIC:
195 virtual_offset = PAGE_SIZE;
196 file_offset = 0;
197 /* Pass PS_STRINGS for BSD/OS binaries only. */
198 if (N_GETMID(*a_out) == MID_ZERO)
199 imgp->ps_strings = aout_sysvec.sv_psstrings;
200 break;
201 default:
202 /* NetBSD compatibility */
203 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) {
204 case ZMAGIC:
205 case QMAGIC:
206 virtual_offset = PAGE_SIZE;
207 file_offset = 0;
208 break;
209 default:
210 return (-1);
211 }
212 }
213
214 bss_size = roundup(a_out->a_bss, PAGE_SIZE);
215
216 /*
217 * Check various fields in header for validity/bounds.
218 */
219 if (/* entry point must lay with text region */
220 a_out->a_entry < virtual_offset ||
221 a_out->a_entry >= virtual_offset + a_out->a_text ||
222
223 /* text and data size must each be page rounded */
224 a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK
225
226 #ifdef __amd64__
227 ||
228 /* overflows */
229 virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX
230 #endif
231 )
232 return (-1);
233
234 /* text + data can't exceed file size */
235 if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
236 return (EFAULT);
237
238 /*
239 * text/data/bss must not exceed limits
240 */
241 PROC_LOCK(imgp->proc);
242 if (/* text can't exceed maximum text size */
243 a_out->a_text > maxtsiz ||
244
245 /* data + bss can't exceed rlimit */
246 a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
247 racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
248 PROC_UNLOCK(imgp->proc);
249 return (ENOMEM);
250 }
251 PROC_UNLOCK(imgp->proc);
252
253 /*
254 * Avoid a possible deadlock if the current address space is destroyed
255 * and that address space maps the locked vnode. In the common case,
256 * the locked vnode's v_usecount is decremented but remains greater
257 * than zero. Consequently, the vnode lock is not needed by vrele().
258 * However, in cases where the vnode lock is external, such as nullfs,
259 * v_usecount may become zero.
260 */
261 VOP_UNLOCK(imgp->vp, 0);
262
263 /*
264 * Destroy old process VM and create a new one (with a new stack)
265 */
266 error = exec_new_vmspace(imgp, &aout_sysvec);
267
268 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
269 if (error)
270 return (error);
271
272 /*
273 * The vm space can be changed by exec_new_vmspace
274 */
275 vmspace = imgp->proc->p_vmspace;
276
277 object = imgp->object;
278 map = &vmspace->vm_map;
279 vm_map_lock(map);
280 vm_object_reference(object);
281
282 text_end = virtual_offset + a_out->a_text;
283 error = vm_map_insert(map, object,
284 file_offset,
285 virtual_offset, text_end,
286 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
287 MAP_COPY_ON_WRITE | MAP_PREFAULT);
288 if (error) {
289 vm_map_unlock(map);
290 vm_object_deallocate(object);
291 return (error);
292 }
293 data_end = text_end + a_out->a_data;
294 if (a_out->a_data) {
295 vm_object_reference(object);
296 error = vm_map_insert(map, object,
297 file_offset + a_out->a_text,
298 text_end, data_end,
299 VM_PROT_ALL, VM_PROT_ALL,
300 MAP_COPY_ON_WRITE | MAP_PREFAULT);
301 if (error) {
302 vm_map_unlock(map);
303 vm_object_deallocate(object);
304 return (error);
305 }
306 }
307
308 if (bss_size) {
309 error = vm_map_insert(map, NULL, 0,
310 data_end, data_end + bss_size,
311 VM_PROT_ALL, VM_PROT_ALL, 0);
312 if (error) {
313 vm_map_unlock(map);
314 return (error);
315 }
316 }
317 vm_map_unlock(map);
318
319 /* Fill in process VM information */
320 vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
321 vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
322 vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
323 vmspace->vm_daddr = (caddr_t) (uintptr_t)
324 (virtual_offset + a_out->a_text);
325
326 /* Fill in image_params */
327 imgp->interpreted = 0;
328 imgp->entry_addr = a_out->a_entry;
329
330 imgp->proc->p_sysent = &aout_sysvec;
331
332 return (0);
333 }
334
335 /*
336 * Tell kern_execve.c about it, with a little help from the linker.
337 */
338 static struct execsw aout_execsw = { exec_aout_imgact, "a.out" };
339 EXEC_SET(aout, aout_execsw);
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